Count how many values in a list that satisfy certain condition

Question

I have the following list,

mylist = [\'0.976850566018849\',
 \'1.01711066941038\',
 \'0.95545901267938\',
 \'1.13665822176679\',
 \'1.21770587184811\',
 \'1.         


        

Answer 1

You can use numpy or pandas, though for such a simple computation they would be much slower than the alternatives mentioned above.

Using numpy,

import numpy as np
arr=np.array(mylist).astype(float)
print len(arr[arr>=1.3])

Using pandas,

import pandas as pd
s=pd.Series(mylist).astype(float)
print len(s[s>=1.3])

Alternatively,

(pd.Series(l).astype(float)>=1.3).value_counts()[True]

For performance, the fastest solution seems to be

In [51]: %timeit sum(1 for x in mylist if float(x) >= 1.3)
100000 loops, best of 3: 8.72 µs per loop